Semaphore-signal.



UNITED STATES PATENT OFFICE.

WALTER W. BROWN, 01 SCI-IENECTADY, NEW YORK, ASSIGNOR, BY MESNE ASSIGN-MENTS, TO THE UNION SWITCH AND SIGNALCOMPANY, A CORPORATION OF PENN-SYLVANIA.

SEMAPHORE-SIGNAL.

Specification of Letters Batent.

Patented Sept. 10, 1912.

The object of my invention is to. provide an exceedingly compact andeconomical structure, which is reliable and eflicient in operation.

It is frequently desirable to provide means for preventing the movementof a signal from danger to clear position, except when it is driven bythe motor, since, if the counter-weight alone is relied upon for holdingthe signal at danger, it may be carried to clear position by tamperingor by the accumulation of snow or ice on the semaphorearm. I secure thedesired result by providing means for permitting a relative movement ofthe semaphore-arm and driving mechanism in one direction only, with abrake for preventing all movement of the driving means except when themotor is operated. In order to permit the relative movement ofsemaphore-arm and driving mechanism in one direction only, I make use ofa pawl and ratchet device connecting the two, which may be added to astandard mechanism without increasing the space required, and withoutmaterially increasing the cost.

In an electrically-operated signal it is ordinarily necessary to providebetween the motor and signal-arm speed-reducing-gearing comprising oneorsmore intermediate shafts. For supporting these shafts, frames,standards, or brackets, within the casing have heretofore been employed.These occupy considerable space and increase the size and cost of thesignal. One feature of my invention consists in journaling theintermediate gear-shafts in the wall of the casing itself, with one gearof each shaft inside and the other outside the casing. I further providea gear-case for the gears Figure 1 shows a side elevation, with the soas to protect them casing in cross-section, of a signal mecha nisma-rranged'in accordance with my invention; and Fig. 2 shows a backelevation of the same.

In the drawings A represents an inclosing casing in which is mounted anelectric motor B. This motor is provided with an electric brake 'C, thecoil of which is connected in series with the motor, as indicated inFig. 1. All the parts in the drawing are shown in the positions whichthey occupy when the motor is in the act of driving the semaphore-armfrom danger to clear, so that the brake-coil G is shown energized,attracting its armature O, and holding it away from the brake-disk D onthe motor shaft. When the motor circuit is broken, the armature C" isreleased. and is pressed by its springs into engagement with thebrake-disk D. Consequently, whenever the motor is deenergized, all partsthat are geared to it are held fast by the brake.

The motor shaft carries a pinion which engages a gear on an intermediateshaft E.

This shaft is journaled in a stud or boss formed in the wall of thecasing itself, and carries a pinion at its end outside the casing. Thispinion engages a gear on a second intermediate shaft E. which issimilarly journaled in the wall of the casing and carries a, pinioninside the casing. A gearcase F covers the gear and pinion outside thecasing, and protects them from the weather: By means of thisconstruction the necessity forsupporting-standards or brackets insidethecasing is avoided, and the size and cost of the signal reduced.

The pinion on the intermediate shaft E engages gear-teeth on theperiphery of a drive-wheel G, which is loosely mounted on the shaft Hwhich is journaled in a boss H in the wall'of the casing and carries thesignal-arm I and its counter-weight or spectacle casting I. For drivingthe signal to clear position the drive-wheel G is clutched to the shaftH by a slot mechanism comprising a locking piece J, adapted to engageprojecting studs G at the periphery of the drive-wheel, controlled bythe actuating magnets K by means of a bell-crank lever L, which ispivoted on an arm L fast to the shaft H, and which carries at the end ofits long arm an armature K for the magnets K, and at the end of itsshort arm is connected to the locking piece J. When armature K isattracted by the magnets K, as shown in the drawings, the locking pieceJ is thrust outward into the path of the studs G, one of which is shownin engagement with the driving piece, so as to drive the shaft H. Whenthe magnets are deenergized, the armature K falls away, withdrawing thelocking piece J, so as to disengage the shaft from the drive-wheel, andto allow the signal to go to danger.

M represents contacts carried at the inner end of shaft H, controllingthe circuits of the motor and slot-magnets in a manner well understoodin the art. The connections of these contacts are not shown in thedrawings. N represents a dash-pot for retarcling the movement of thesignal when it is carried to danger by its counter-weight.

In order to prevent the signal-arm from being carried to clear positionfrom any cause, except when the motor is operating, I provide aspring-pressed pawl O on the shaft H, and ratchet-teeth on the hub ofthe drive-wheel Gr adapted to be engaged by the pawl. When the motor isoperating to drive the signal to clear, as shown in the drawings, therotation of the drive-wheel G for this purpose being counter-clockwise,as viewed in Fig. 2, the ratchet and pawl are inoperative, since theyare carried along together by the engagement between the locking piece Jand a stud G on the drivewheel. When the slot-magnets K are deenergizedto allow the signal to go to danger, the pawl and ratchet device stillremains inoperative, since the rotation of the shaft, when the signal ismoved toward danger position, is clockwise, as viewed in Fig. 2, so thatthe pawl O slips idly over the ratchet-teeth. But as soon as the signalreaches danger posit-ion it is locked there by the pawl O, whichprevents any movement of the semaphore-arm relative to the drivewheel inthe opposite direction, while the drive-wheel is prevented from allmovement whatever by the brake on the motor shaft,

which is now released by its coil. Consequently the semaphore-arm islocked at danger position, and cannot be moved to clear until the motoris energized to drive it; at which time the brake-coil C is energizedand the drive-wheel G driven by the motor. It will be noted that theratchet and pawl device employed adds nothing to the space required andvery little to the cost of the apparatus.

I do not desire to limit myself to the particular construction andarrangement of parts here shown, but aim in the appended claims to coverall modifications which are within the scope of my invention.

That I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. In a semaphore signal, a semaphorearm, a driving member, a slotmechanism for clutching said member to said arm, means for preventingrelative movement of said arm and member in one direction only, adriving motor for said member, a brake for said member, and means forrendering said motor and said brake alternately operative.

2. In a semaphore signal, a drive-shaft, a semaphore-arm carriedthereby, a driving member loose on said shaft, a slot mechanism forclutching said member to said shaft, means for preventing relativemovement of said shaft and member in one direction only, a driving motorfor said member, a brake for said member, and means for rendering saidmotor and said brake alternately operative' 8. In a semaphore signal, adrive-shaft, a semaphore-arm carried thereby, a driving member loose onsaid shaft, a slot mechanism for clutching said member to said shaft, aratchet and pawl device connecting said member to said shaft, a drivingmotor for said member, and means for preventing the movement of saidmember except when the motor is operating.

In witness whereof, I have hereunto set my hand this 20th day of March,1907.

WALTER W. BROWN.

Witnesses BENJAMIN B. HULL, HELEN ORFORD.

4 Copies of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents,

